Driverless vehicles of the general type involved herein are disclosed in U.S. Pat. No. 3,356,040. As disclosed in said patent, a driverless vehicle is propelled along tracks by frictional contact between a rotating drive shaft and a drive wheel on the vehicle.
When the load on such a driverless vehicle is light, only one drive wheel is adequate. For larger loads, it is known to provide two drive wheels on a vehicle with the drive wheels being connected together. For example, see U.S. Pat. No. 4,347,792. Curves in the tracks has caused some concern in connection with such driverless vehicles. For example, see U.S. Pat. No. 4,389,943 which discloses a set of bogies on the driverless vehicle so that it may negotiate curves without a jerky motion. It is known to control the speed of such a driverless vehicle by providing a speed control device usually in the form of a cam for cooperation with a cam follower attached to the drive wheel. For example, see U.S. Pat. No. 4,348,961.
The present invention is directed to solution of the problem of how to provide a train of such driverless vehicles. A train of such driverless vehicles differs from a conventional train in that each vehicle is separately propelled by contact between its drive wheel and the drive shaft associated therewith. If it is desired to cause the train to stop with the support wheels of the lead vehicle on a curve and one or more of the remaining cars on a straight section of the track, it has been found necessary to interconnect the drive wheels on the vehicles of the train with a flexible member.